The disclosures herein relate generally to computer systems and more particularly to assembly of modules during the manufacture of computer systems.
Manual insertion of dual inline memory modules (DIMMS) by a test operator for the purpose of functionally testing motherboards has proven in the past to cause extensive damage to the motherboards and the DIMMS resulting in increased costs to manufacturers. One prior method to address this problem was to install the DIMMS onto an interface card located beneath the motherboard and connect the DIMMS by means of electrical traces and test probes.
Another prior method was to install a xe2x80x9csacrificexe2x80x9d or xe2x80x9cthrow awayxe2x80x9d board between the DIMMS and the motherboard thereby increasing the life span of the DIMMS. This solution does not address the damage incurred to the motherboards during test. Due to the greater bus speeds encountered on more current DIMMS and RAMBUS inline memory modules (RIMMS) the above-mentioned method will no longer suffice.
In U.S. Pat. No. 4,357,575, a testing fixture apparatus for use in accurately effecting temporary electrical connections with the test point zones of printed circuit boards or the like is provided. The board to be tested is mounted upon a locator assembly that is receivable within the fixture, and includes a centering and gripping mechanism for automatically positioning the locator assembly and printed circuit board in a predetermined location within the fixture. This assures precise alignment of a contact with each of the test point zones of the printed circuit board to be tested. The positioning action of the mechanism and its cooperating part includes both a centering function and a gripping function therebetween. Both of these functions occur automatically in response to relative shifting of the portions of the fixture for respectively supporting the printed circuit board and the contacts toward each other into an operative relationship, for effecting electrical connections between the test point zones of the printed circuit board and corresponding contacts of the fixture.
In U.S. Pat. No. 5,485,096, there is disclosed a printed circuit board test apparatus which has a test bed formed by a planar member having a plurality of through channels at close spacing across its surface to receive test probes. Each of the test probes comprises a tubular body having a top contact surface and a socket at its opposite end. A plurality of planar switch cards are provided with each card for supporting, along one edge thereof, a plurality of pins which are disposed in rows at locations corresponding to the predetermined locations of the through channels of the test board. Each switch card has a plurality of electrical circuits which interconnect with selected pins and which are connected to selected contacts of a connector located at another extremity of the switch card. The switch cards are supported with the ends of the pins received in recesses of the test probes, thereby establishing conductive paths from the surface contacts of the probes to the connector of the card. Each switch card is connected to the remainder of the test circuitry of the test equipment. Preferably, components such as switching circuits are mounted on the switch cards to control the test functions of the test equipment.
In U.S. Pat. No. 5,698,990, a counterforce spring assembly for printed circuit board test fixtures is provided. A number of counterforce spring assemblies are provided in an array between the top plate and probe plate of the test fixture. Each counterforce spring assembly includes a support cup residing in an aperture through the probe plate. A compression spring resides in the support cup and provides spring-biasing of the top plate to the probe plate during the testing cycle of the unit under test (UUT). Each counterforce spring assembly includes a circumferential flange to limit downward travel of the top plate toward the probe plate. Each assembly is small enough to fit between probe apertures corresponding to component leads of the UUT. The counterforce spring assemblies can be freely placed underneath the top plate to provide even spring-biasing thereof to prevent bowing and bending of the top plate, which often causes errors in the testing of printed circuit boards.
Therefore, what is needed is a PC card clamping device for an automated test fixture which maintains the card or cards straight and aligned for automatic insertion into mating connectors provided on a UUT.
One embodiment, accordingly, provides a clamping device formed of two plates which are adjustable to retain and straighten the PC cards for use in a test fixture. To this end, a PC card clamping apparatus includes a base member having a plurality of slots formed therein. A clamp member includes a plurality of ribs formed therein seated for lateral movement in the slots. A fastener, which is removable, extends through the base member and the clamp member. The fastener is adjustable for moving the ribs laterally in the slots and retaining the clamp member on the base member.
A principal advantage of this embodiment is that the PC card is retained in a straightened manner so that bowing of the card does not occur. Another advantage is that multiple cards may be retained in parallel and in alignment with their respective connectors.